The subject matter disclosed herein relates to valves and, more particularly, to pneumatically actuated valves and pressure regulators therefor.
Bleed systems, such as those for aircraft, generally involve taking compressed air from an engine, and converting it to various temperatures and pressures suitable for one or more uses. Pressure is usually managed through one or more bleed control valves, such as butterfly valves. Depending on the aircraft configuration, bleed control valves can be generally controlled either pneumatically, electronically, or both via through proportional and/or integral feedback control loops.
Pneumatic control is done through physical components, flow passages, levers, etc., while electronic control utilizes electrical signals. An electronically controlled proportional valve generally is operated by receiving an electrical control signal which corresponds to a valve position. An electronically controlled integrating valve is controlled with an electrical signal that corresponds to a valve velocity, causing the valve to open or close due to the valve travelling at a velocity for a certain amount of time.
Maintaining stable bleed system pressures can improve performance and decrease valve wear. Bleed system pressures can be stabilized, for example, by resisting cycling and input disturbances in the system. At the same time, actuator components are prone to particulate damage from fluids being drawn in from the flow duct. Constant actuator fluid supply pressure improves proportional control of pneumatically actuated valves and prevents fluttering of the closure element or disk. Existing systems for regulating valve actuation pressure can require separate regulator units and filter units which take up needed space on the valve assembly and add weight.